This document summarizes faults reported from various S7 HP and TMW2100 transmitter sites in India. For S7 HP sites, chronic faults included PA failures, fuse blowing, optocoupler failures, and issues with the water circulation system. Occasional faults were encoder card and daughter board problems. For TMW2100 sites, the only reported problem was fuses frequently blowing without reason and lightning arrestor failures. General maintenance tips included keeping transmitters dust-free, ensuring proper connectivity, adequate air circulation, and promptly investigating any abnormalities or unexplained tripping.

1. Discussion
on
Faults in S7 HP and TMW2100 Transmitter
by
R.Narasimha Swamy,
Superintending Engineer, AIR, Bangalore

3. Fault reports compiled from
• S7HP sitesS7HP sites
– ImphalImphal
– Sri NagarSri Nagar
– JodhpurJodhpur
– IndoreIndore
– NagpurNagpur
– CuttackCuttack
– NajibabadNajibabad
– KargilKargil
• TMW2100 SitesTMW2100 Sites
– CuddapahCuddapah
– PortblairPortblair
– NangliNangli
– KohimaKohima
– RaipurRaipur

4. Chronic faults in S7 HP
• PA failure (Utilise the test jig available at Nagpur for
servicing).
• Blowing of fuses of PA, failure of SMD capacitors in series
with the output torroid, power supply clips of the PA VDD
supply.
• Failure of opto couplers (Refer Indore modification).
• Problem in water circulation system due to corrosion and
scale formation in the pipe lines. (consider using distilled
water, chemical pumps for pressurization)
• Failure of polling mechanism due to problem in distribution
board.
• Failure of SILPAD.

5. Occasional faults in S7 HP
• Failure of Encoder card connectivity
• Problems/failures in daughter board
• Failure of PS of driver module
• Problem in VCC (PS 323, A1, +5V) of Encoder board
• Micro switch problem of KM1 and KM2
• Failure of torroidal transformer

6. Problems in TMW2100
• No chronic problems.No chronic problems.
• The 600V/12.5A fuse [FS-1to FS-20] blows offThe 600V/12.5A fuse [FS-1to FS-20] blows off
very frequently without any reason.very frequently without any reason.
• Failure of lightning arrestors (surge protectors).Failure of lightning arrestors (surge protectors).
• Refer to Thales service engineers report of Port BlairRefer to Thales service engineers report of Port Blair
installation.installation.

7. General maintenance tips
• Keep transmitter free from dust and suit.
• Ensure proper connectivity.
• Air conditioning/circulation is must.
• Introduce, if necessary additional, properly rated
surge/lightning protectors (MOV and valve type) on mains
and DC power supplies.
• Keep a watch on the feeds and investigate the matter
immediately, in case of abnormality.
• Do not ignore faults which includes tripping of the
transmitter without indication.

8. Thank you